A “levered” or “trailing arm” type landing gear has a main fitting connected to the fuselage of an aircraft, and a trailing arm that is pivotally connected to the main fitting. The trailing arm carries a wheel assembly. When the aircraft lands, landing loads cause the trailing arm to pivot relative to the main fitting. A shock absorber, which is generally an oleo-pneumatic shock absorber, is provided between the main fitting and trailing arm to provide spring and damping functions.
While oleo-pneumatic shock absorbers provide efficient shock absorption, they are generally sensitive to oil and/or gas loss. As such, they require regular maintenance.
It is known to provide an aircraft landing gear with a mechanical spring. A mechanical spring advantageously does not require oil and gas maintenance. However, a mechanical spring is generally heavier than an equivalent gas or liquid spring.